Leap Year Calculator
Enter any year to find out whether it is a leap year, the reason behind it, and when the next leap years fall.
Last updated: June 20, 2026 · Reviewed by TG we-Calculate Editorial TeamNo — 2026 is not a leap year. It is not divisible by 4.
- 1
Year mod 4
2,026 mod 4 = 2Non-zero — common year, no further checks needed. - 2
Days in February
28
How do you know if a year is a leap year?
A year is a leap year if it is evenly divisible by 4, except for century years (those divisible by 100), which must also be divisible by 400. So 2024 and 2000 are leap years, but 1900 and 2100 are not. Leap years have 366 days, with 29 days in February.
Formula
How this is calculated
The only input is a whole calendar year. The calculator applies the Gregorian leap-year rule, which is a chain of divisibility (modulo) tests. First it checks whether the year is divisible by 4: if not, it is a common year. If it is divisible by 4, it then checks the century exception — years divisible by 100 are normally skipped, so 1900 and 2100 are common years even though they divide by 4.
The exception itself has an exception: years divisible by 400 (like 1600 and 2000) are leap years after all. Combining the tests, a year is a leap year when it divides by 4 and either does not divide by 100 or does divide by 400. A leap year has 366 days with 29 days in February; otherwise the year has 365 days and 28 days in February.
The rule exists because a solar year is about 365.2422 days, so a plain 4-year leap cycle slightly over-corrects; dropping three leap days every 400 years keeps the calendar aligned with the seasons. This tool assumes the proleptic Gregorian calendar for all years and does not account for the historical Julian calendar used before 1582 or local adoption dates.
Examples
| Input | Result |
|---|---|
| 2024 | Leap year — divisible by 4 and not a century year (29 days in February). |
| 1900 | Common year — divisible by 100 but not by 400 (28 days in February). |
| 2000 | Leap year — divisible by 400, so the century exception is overridden. |
Frequently asked questions
A solar year is about 365.2422 days, so adding a day every 4 years slightly over-corrects. Skipping the leap day in century years not divisible by 400 keeps the calendar aligned with the seasons.
No. 2026 is not divisible by 4, so it is a common year with 365 days and 28 days in February. The next leap year is 2028.
Roughly every 4 years. Over a full 400-year Gregorian cycle there are 97 leap years (not 100), because three century years are skipped.
Also known as
Sources & references
TG we-Calculate Editorial Team. (2026). Leap Year Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/leap-year-calculator
TG we-Calculate Editorial Team. "Leap Year Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/leap-year-calculator.
TG we-Calculate Editorial Team, "Leap Year Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/leap-year-calculator
@misc{wecalculate_leap_year_calculator, title = {Leap Year Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/leap-year-calculator}}, year = {2026}, note = {TG we-Calculate} }
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